Sample preparations in medical diagnostics, the pharmaceutical industries, chemical industries as well as people doing DNA work require many precise liquid handling steps, such as: transfer of samples, dilutions, additions of reagents, transfer of reaction mixtures, etc. Automated liquid handling systems have been developed and are commercially available in the form of programmable pipetting work stations. These automated systems reduce the manual labor involved in the liquid handling and processing of samples. See for example, U.S. Pat. No. 6,033,911, owned by applicant.
However, these systems are not completely automatic and still require manual manipulation and user intervention, especially when using a manual vacuum manifold system with the pipetting work station. The processing of liquids still requires human intervention and manual manipulation. Typically, the user is required to place a filter plate on top of the manual vacuum box and then the filter plate is filled with a plurality of samples. Once the filter plate is filled with samples, the user has to manually manipulate the vacuum during the wash steps of the extraction process. Once the wash step of the extraction process is completed, the user carefully removes the filter plate containing the remaining constituents which are being collected. The user then places a collection plate into the vacuum box and then places the filter plate on top of the collection plate and then manually manipulates the vacuum to extract the constituent of interest. Thus, the user is constantly interacting with the system during the collection of samples.
Thus, existing systems have short comings that limit their efficiency. For example, some analytical laboratories process hundreds of samples using solid phase extraction or other techniques. Since the steps are highly repetitive, automated systems are needed to reduce the manual labor involved in the liquid handling and processing steps. In addition, user intervention and manual operations reduce the efficiency of an otherwise automated analytical system.
Therefore, there is a need for an apparatus and method for performing analytical procedures without the need for operator intervention and minimizing the manual tasks before, during and after the analytical procedures.
In addition, there is a need for an apparatus and method which provides automated vacuum control to enhance flow rates through the sorbing media or frit, thus providing good recoveries and throughput of flow rate dependent compounds. In addition, a system having an automated variable vacuum control would mitigate well to well cross talk tendencies.
The following prior art reflects the state of the art of which applicant is aware and is included herewith to discharge applicant's acknowledged duty to disclose relevant prior art. It is stipulated, however, that none of these references teach singly nor render obvious when considered in any conceivable combination the nexus of the instant invention as disclosed in greater detail hereinafter and as particularly claimed.
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